Control Module: Description and Operation

4AT Control Unit:

The 4 A/T Control Unit, located under the dash left of the steering column, is the control unit for various electrically operated functions of the N4A-HL automatic transmission.

To coordinate engine operating conditions with transmission functioning, the ECU informs the 4 A/T control unit of engine throttle position (throttle sensor). The control unit in turn utilizes this information in its calculations for functions such as gear selection, kickdown and torque converter lockup.